Improvement in blast apparatus for furnaces



W. A; STEPHENSl 'BLAST APPARATUS Fon FURNACE. v N0.177,0Z8. A rammed May 2,1876.

Fly. 7.

NJEERS, PNUTO-UTHQGRPHEH. WASHINGTON, D C.

Suckasunny Plains,.in.-the county of Morris and. State of'New- Jersey, have invented anew 4applied for Letters. Patent, March 4, 18,75.;

' -culiar meansiadaptedlfor increasing theforce directly above the furnace proper, and sup- -frnn GFFIGE.,

TO WILLIAM MOLLER,"

@MPRQVEMENT 1N: BLAST APPARATUS Fon FnRNA'cE-s.

on NEW YORK, N. Y.-

specificanonforming,part 0f Letters-PatentN0.177.o2s, dated Maya, 1816 application man i December 3, 1875..

.170A all whom it. mag/conectan l Beit knowneth atl, WILLIAM A. STEPHENS,

and useful Improvememt.,in` BlastfFurnaceS; andL do .hereby declare. that the following iS aifnll. andrexaetdescription. of the same, ref'ereneebein ghad tothe accompanyingA drawings, anditothelettersof referenceimarked thereon.

The-'ohiectof my invention is. an. improvement upon the hot-blast furnacefor which I .andtt-heginvention thereinconsists inthe peandeflieiency-of the hot blast.I and, the durability of theparts cennectedl with the same, v

:with a. suitable blower, is a blast-pipe, E, from whichbranches apipe, F, which enters and also in4 the: various operative.4 combinations connected with the same, all as more fully hereinafter described.

In; .the drawings making a part of this specification, Figure-.1 is. av verticalk section.. of the.wholeap-paratus.; FiglZ,` a. vertical section.A of a; portion-pf thetopof the. heater, the duce, and..tuyere. showin gthe blastpipe withinftheheater andtheduct.

Likelettersdenote corresponding parts-.in each, figure..

Aedenotes the furnace proper, adapted for use with.,l anthracite coal, and with. ahot blast alone, preferably of the forntshown, incased in brick and covered withv a shell, preferably of boiler-iron; B, the roasting-oven, placed ported upon hollow supports C 0,.,three or more in number, leading ontof the upper part of the furnace proper, yand entering the bottom of the roasting-oven, and serving as lines to conduct the gases of combustion from the furnace proper into the roasting-oven. This roasting-oven is furnished with proper chutes a, orifices b to admit air for combustion of gases, doors c to clear ont the oven, or introduce instruments to stir up or loosen the contents of the oven, a damper-cover, d, capable of convenient operation from the outside, to regulate the escape of heat or gases from the roasting-oven, a swing-door, e, in the bottom, to allow the charge to fall out, and a pivoted scraper or partition, f, adapted to beoperated from the outside, and intended to separate successive charges of ore placed in the roasting-oven. This roasting-oven, moreover, is ineased with brick-work,and also the supports, with ashell. around the same, the same as the. furnace proper, which'brick-work, extended above said ovenforms thetop of the stack or Hue of the furnace. The furnace A. has apivoted coveror door, g, beneaththatin thebottOmof the roasting-oven, and suitable openings for cleaning out the same and per mitting the melted contents to flow out. Around this furnace proper are arranged two orimore'heaters, D, adapted to burn anthracite coal,...having.a com-bustionchamber,` D, dome-shaped or reverberating.. l p

Upon the outside of each heater, connected the.. h eater below the lire-bed, and aids in combustion of the coalv therein, and another branch or blastvpipe, G, which enters the :combustion-chamber, passes around the saine in coils, and: through and Y acrossthe combusf tion-chamber intoV a` duct, H, and along within the Same toward. the furnace, and'nearly tol the end of the duct. These several pipes have proper,regnlatingfvalves,

properly secured a .conical deflector, I, madeof Wrought-iron or refractory material, with its mouth toward the end of the blast-pipe G,

which approaches quite near the center of it,-

and having an opening, h, for the, passage through it of the hot air from the blast and the gases contained in the duct. This dcleetor, itv is to be observed, fits as tightly as i possible in the duct, so that there is no airpassage around its periphery. 4At the end of of the duct is secured, in any suitable manner, another duct, J, iliade of wrought-iron or of refractory material, having an inside diameter at least equal to the inside diameter of the smallest end ot-the ductH, and preferably turned upa little at k, so as to assume a hortuyere from its heel to its front, then bent,

back, as at j, along over the main body of the coil, so Vthat the water, entering, passes along the. pipe at j, and is presented first at the front of the tuyere, and then circulates around it backK toward its heel, thus presenting the coldest water at the part where the heat is the greatest.

' 0n the under sid-e of the duct J, at the angle 7c, is an opening, m, passing directly into said duct, and closed -by a suitable plug or other equivalent means, the object of which opening is twofold, being to enable the operator to thrust in a rod, preferably of zinc, in order to test, by melting it, the degree of heat within said duct, and also to enable the operator to introduce a rod to clear out the interior of the tuyere.

In the operation of my apparatus the same course is followed with regard to starting the l, last chargin g the roasting-oven,'heatiug and charging athe furnace proper, and in manipulation generally, as is described in the application of 4March 4, 1875, previously referred to.

" In the'special operation of the blast ittwill be perceived that, the coils of the blast-pipe in the combustion-chamber becoming intensely heated, the air within such pipe becomes corair-force exerted through the branch pipe F,

and compressed by the diminishing size of the duct H, and forces said gases through the orice h in the deflector I. Immediately upon their passage throughthe orifice named the gases take tire, and there occurs instantaneously an expansion in volume of them, limited by the greater interior. area of the duct J as comparedwith the area of the orifice h. In this expansion the inclination of the gasesin combustion to force themselves back into the duct H is controlled and prevented by the interposition of the outside walls of the detlector, which present shoulders against `such back pressure, and include between themselves and Ithe inner walls of the duct H recesses or chambers n, which receive and sustain theback pressure. This back pressure is, however, less than the forward Vpressure through the orifice JL, and therefore the forward movement of the blast is uninterrupted. The advantages ofy my peculiar construction and arrangement of the various ducts, the b1astpipe, and the deflector are, that I amoenabled to develop a greater degree of heat in the blast than has heretofore been had, which is of the utmost consequence in the reduction `of ironl ores by anthracite coal, as it not only makes the reduction quicker, cheaper, but produces a better quality of mig, inasmuch as, by the increased temperature of the blast, `Iam enabled, under comparatively low air-pressure, to force-'burning `gases into the coal in the furnace proper, and to force fresh gases arising out of the combustion of the coal in the furnace proper into the roasting-oven, there to i take fire again, and roast and desulphurize the ore contained therein. y operation of smelting is performed upon ores which have been desulphurized and "deoxidized by anthracite coals which have been in a great measure deprived of gases which would injure the quality of the iron. i

Having thus described my apparatus and its mannerV of operation, whatI claim as new therein and my invention is i 1. In combination with the ducts H and J and deiector I, the opening M placed directly at the rear of the deflector and adapted to give access to the interior of the tuyere, substantially as and for the purposes described.

2. In combination, the blast pipe G, the ducts II and J, and the detlector I, 'substantiall y as and for the purposes set forth.

This specification signed and witnessed this 24th day of` November, 1875. Y f

Witnesses:

S. B. GooDALE, v GILBERT SMITH.

At the same time the 

